when adding text or stamp annotations in the annotation viewer, the user can create them by dragging a "size box", or click once to get a annotation with a default size. The stamp annotation for example seems to have the fixed default size of 288x96 pixels (regardless of the underlying image), when adding it by clicking once.
Is it possible to change this default size somehow? I've tried to set the Size property of AnnotationData and AnnotationView objects, but they are obviously ignored for this case.

And what exactly does the "AutoSize"-property do? Even if set to false, the stamp annotation automatically resizes the content if the size is changed.